I'm trying to figure out how I upgraded machines from Windows 8.1 to Windows 10 without downloading the installation files every time. I have tried Mediacreator and create media. But then I have to enter a license which I dont have.
SOLUTION: You cannot do a offline upgrade "WINDOWS 10" from USB/ISO. You have to use the Media Creator for Windows 10 and upgrade windows 7,8,8.1 before running clean install. If you already have upgraded your computer, you can use ordinary ISO files downloaded from www.microsoft.com. To do an "OFFLINE" install you have to have the "tech bench" kit. Think I got it just because I'm a retailer. Correct me if I'm wrong!